CN114449425A

CN114449425A - Micro-electro-mechanical microphone earphone system with noise reduction function and operation method thereof

Info

Publication number: CN114449425A
Application number: CN202011204170.3A
Authority: CN
Inventors: 杨思杰; 文亚南; 周欣瑞
Original assignee: Zhang Suxing
Current assignee: Zhang Suxing
Priority date: 2020-11-02
Filing date: 2020-11-02
Publication date: 2022-05-06

Abstract

A micro-electromechanical microphone earphone system with noise reduction function and an operation method thereof are provided, two or three wires are provided to connect a sound source end host and an earphone device, at least one wire of the wires is used for transmitting music signals, the other wire of the wires is a grounding wire, and the earphone device is driven in a differential voltage or offset voltage mode. The micro-electromechanical microphone in the earphone device has active anti-noise processing capability, and received environmental noise is not required to be transmitted to the sound source end host through an additional line for operation, so that the technical effects of reducing line loss, cost and signal delay are achieved.

Description

Micro-electro-mechanical microphone earphone system with noise reduction function and operation method thereof

Technical Field

The invention relates to an active anti-noise system and an operation method thereof, in particular to a micro-electro-mechanical microphone earphone system with a noise reduction function and an operation method thereof.

Background

In recent years, with the popularization and vigorous development of semiconductor technology, the miniaturization of various electronic components has not been a problem, and at the same time, portable devices or mobile devices can achieve the purpose of being light and thin without sacrificing functionality, or electronic products originally having space limitation can accommodate more electronic components to provide more functions, for example: an earphone.

Generally, a conventional earphone receives a sound signal from a sound source to be played through a sounding unit. However, since various environmental noises exist in a living environment, it is easy to cause a situation where a listener feels that sound is not clear enough. Therefore, manufacturers have proposed using a microphone independent from the earphone or a micro-electromechanical microphone disposed inside the earphone to receive the ambient noise and transmit the ambient noise to the audio source host through a wire to generate an acoustic signal with a phase opposite to that of the ambient noise, so as to cancel the ambient noise with the anti-noise signal while playing music. However, such a structure has (1) line loss, (2) high cost, and (3) signal delay problems, which are further described below:

(1) the output of the sound at the first stage after passing through the mems microphone is usually much less than 1 volt, and if the sound is not subjected to any amplifier or signal format conversion, the voltage is distorted during the transmission process of the wire, which is called the line loss (or simply "line loss"). The line loss may cause the sound signal to be incompletely restored, and thus the environmental noise cannot be effectively eliminated.

(2) The microphone and the audio source end host are connected by wires, which is a necessary cost in terms of mechanism. In addition, in order to avoid line loss, the additional amplifiers or signal format converters added to the system also increase the manufacturing cost. In addition, the micro-electromechanical microphone needs to be powered, so that the current method needs to independently pull a power line from the sound source end host to the earphone device to power the micro-electromechanical microphone in addition to a wire for transmitting the environmental noise.

(3) The process time of ambient Noise from the earphone shell to the human ear is short through the transmission of air, and the so-called Noise reduction technology is that Noise (Noise) is collected from a microphone as soon as possible in the limited time, then an inverted signal is generated through circuit operation, and finally sound waves for canceling the Noise are emitted by a sound generating device. However, in the above-mentioned structure, when the audio signal is transmitted, the format conversion and signal processing of the packet will generate delay, which will prevent the high frequency noise from being eliminated in real time, and further affect the user experience.

In view of the above, it is known that the prior art has problems of line loss, high cost and signal delay for a long time, and therefore, there is a need for an improved technical solution to solve the problems.

Disclosure of Invention

The invention discloses a micro-electro-mechanical microphone earphone system with a noise reduction function and an operation method thereof.

First, the invention discloses a micro-electromechanical microphone earphone system with noise reduction function, comprising: sound source end host computer and earphone device. The audio source terminal host is used for providing two or three wires, wherein at least one wire of the wires transmits music signals, and the other wire of the wires is a grounding wire. Then, in the earphone device, it includes: microcomputer electric microphone and sound production module. The microelectromechanical microphone includes: receive noise module and initiative noise proof module. The noise receiving module is electrically connected with the conducting wire and continuously receives the ambient noise through the sound receiving element so as to generate an ambient sound wave signal corresponding to the ambient noise; the active anti-noise module is electrically connected with the noise receiving module and the conducting wire and used for receiving the music signal from the conducting wire for transmitting the music signal, generating an inverse sound wave signal with the phase opposite to that of the environmental sound wave signal and transmitting the inverse sound wave signal and the music signal; and the sound production module is electrically connected with the active anti-noise module and used for receiving the anti-phase sound wave signal and the music signal, and the sound production monomer is used for simultaneously playing the received anti-phase sound wave signal and the music signal, so that the played anti-phase sound wave signal counteracts the environmental noise.

In addition, the invention also discloses a micro-electromechanical microphone earphone operation method with the noise reduction function, which is applied to the environment with a sound source end host and an earphone device, and comprises the following steps: the sound source end host machine is provided with two or three wires, wherein at least one wire of the wires transmits music signals, and the other wire of the wires is a grounding wire; the earphone device is electrically connected with the sound source end host through the conducting wire so as to receive music signals from the sound source end host; the earphone device continuously receives the ambient noise through the micro-electro-mechanical microphone with the noise reduction function and generates an ambient sound wave signal corresponding to the ambient noise; the micro-electro-mechanical microphone generates an inverse sound wave signal with a phase opposite to that of the environment sound wave signal, and transmits the inverse sound wave signal and the music signal to the sound production monomer arranged in the earphone device; the earphone device simultaneously plays the received reverse sound wave signal and the music signal through the sound production monomer, so that the played reverse sound wave signal counteracts the environmental noise.

The system and method disclosed in the present invention are different from the prior art in that the present invention provides two or three wires to connect the audio source end host and the earphone device, at least one of the wires is used to transmit music signals, and the other wire is a ground wire, and the earphone device is driven by differential voltage or offset voltage. The micro-electromechanical microphone in the earphone device has active anti-noise processing capability, and received environmental noise is not required to be transmitted to the sound source end host machine through an additional line for operation.

Through the technical means, the invention can achieve the technical effects of reducing line loss, cost and signal delay.

Drawings

Fig. 1 is a system block diagram of a mems microphone headset system with noise reduction function according to the present invention.

Fig. 2 is a flowchart of a method for operating a mems microphone headset with noise reduction according to the present invention.

Fig. 3 is a schematic diagram of a first embodiment of the present invention.

Fig. 4 is a schematic diagram of a second embodiment of the present invention.

Fig. 5 is a schematic diagram of a third embodiment of the present invention.

Fig. 6 is a schematic diagram of a fourth embodiment of the present invention.

Wherein, the reference numbers:

110 sound source end host

120 earphone device

121 micro-electromechanical microphone

121a first microelectromechanical microphone

121b second microelectromechanical microphone

122 sound production module

131 receive noise module

132 active anti-noise module

311,411,511,611 first conductor

312,412,512,612 second conductor

313,513 third conductor

Step 210, providing two or three wires for the audio source host, wherein at least one of the wires transmits a music signal, and the other wire is a ground wire

Step 220, the earphone device is electrically connected to the sound source end host through the conducting wire to receive the music signal from the sound source end host

Step 230, the earphone device continuously receives an ambient noise through at least one micro-electromechanical microphone with noise reduction function, and generates an ambient sound wave signal corresponding to the ambient noise

Step 240, the micro-electro-mechanical microphone generates an inverse sound wave signal having a phase opposite to the phase of the ambient sound wave signal, and transmits the inverse sound wave signal and the music signal to a sound generating unit disposed in the earphone device

Step 250, the earphone device simultaneously plays the received inverse sound wave signal and the music signal through the sounding unit, so that the played inverse sound wave signal counteracts the environmental noise

Detailed Description

The following detailed description will be made in conjunction with the accompanying drawings and embodiments of the present invention, so that how to implement the technical means for solving the technical problems and achieving the technical effects of the present invention can be fully understood and implemented.

First, before describing the mems microphone headset system with noise reduction function and the operating method thereof, the environment in which the present invention is applied will be described, the present invention is applied to a headset device, and only two or three wires are used to connect the headset device and a sound source terminal host, so as to achieve active noise immunity and reduce line loss, cost and signal delay through the improved power supply mode.

Referring to fig. 1, fig. 1 is a system block diagram of a mems microphone headset system with noise reduction function according to the present invention, the system including: an audio source host 110 and an earphone device 120. The audio source host 110 provides two or three wires, at least one of the wires transmits a music signal, and the other wire is a ground wire. In practical implementations, the wires may include a first wire, a second wire, and a third wire, wherein the first wire transmits a music signal, the second wire transmits a power Voltage (VDD), and the third wire is a Ground (GND). In addition, the first wire and the second wire may be used to transmit music signals as differential signals, and the earphone device 120 is driven by differential voltage, and the third wire is also used as a ground wire. In addition, the wires may include only a first wire and a second wire, wherein the first wire transmits a music signal having a direct current offset (DC offset) and drives the earphone device 120 with an offset voltage, and the second wire is a ground wire.

Then, in the earphone device 120, it includes: a micro-electromechanical microphone 121 and a sound generation module 122. The mems microphone 121 includes: a noise receiving module 131 and an active noise resisting module 132. The noise receiving module 131 is electrically connected to the conductive wire and continuously receives the ambient noise through the sound receiving element to generate an ambient sound wave signal corresponding to the ambient noise. In practical implementation, the sound receiving device is electrically connected to an Analog Front End (AFE), a digital-to-digital converter (ADC), the active noise cancellation module 132 and an amplifier in sequence. It should be noted that the earphone device 120 may further include another micro-electromechanical microphone electrically connected to the micro-electromechanical microphone 121 and the conductive wires, and continuously receiving the residual noise to generate a corresponding error signal, and transmitting the error signal to the micro-electromechanical microphone 121 for the active anti-noise module 132 to perform the delay compensation process.

The active anti-noise module 132 is electrically connected to the noise receiving module 131 and the conductive wires, and is configured to receive the music signal from the conductive wires transmitting the music signal, generate an opposite phase sound wave signal opposite to the phase of the environmental sound wave signal, and transmit the opposite phase sound wave signal and the music signal together. In other words, the generated opposite phase acoustic wave signal is 180 degrees out of phase with the ambient acoustic wave signal. In actual implementation, the active anti-noise module 132 may include: anti-phase (Anti-phase), Delay (Delay), Gain (Gain), time control, Equalization (Equalization), signal superposition, format conversion, and Filtering (Filtering) for noise processing and music signal processing.

The sound generation module 122 is electrically connected to the active anti-noise module 132, and is configured to receive the anti-phase sound wave signal and the music signal, and simultaneously play the received anti-phase sound wave signal and the music signal through the sound generation unit, so that the played anti-phase sound wave signal counteracts the ambient noise. In practical implementations, the sound-emitting monomer may comprise: electromagnetic (electromagnetic), piezo (piezo), capacitive (Electrostatic), Plasma (Plasma), and the like.

In particular, in practical implementation, all modules described in the present invention can be implemented by various manners, including software, hardware, or any combination thereof, for example, in some embodiments, each module can be implemented by software, hardware, or any combination thereof, and besides, the present invention can also be implemented partially or completely by hardware, for example, one or more modules in a System can be implemented by an integrated circuit Chip, a System on Chip (SoC), a Complex Programmable Logic Device (CPLD), a Field Programmable Gate Array (FPGA), or the like. The present invention may be a system, method and/or computer program. The computer program may include a computer readable storage medium having computer readable program instructions embodied thereon for causing a processor to implement various aspects of the present invention, the computer readable storage medium may be a tangible device that can hold and store the instructions for use by the instruction execution device. The computer readable storage medium may be, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: hard disk, random access memory, read only memory, flash memory, compact disk, floppy disk, and any suitable combination of the foregoing. Computer-readable storage media as used herein is not to be construed as transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission medium (e.g., optical signals through a fiber optic cable), or electrical signals transmitted through a wire. Additionally, the computer-readable program instructions described herein may be downloaded to the various computing/processing devices from a computer-readable storage medium, or over a network, for example: the internet, local area network, wide area network and/or wireless network to an external computer device or external storage device. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, hubs and/or gateways. The network card or network interface in each computing/processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in a computer-readable storage medium in the respective computing/processing device. The computer program instructions which carry out operations of the present invention may be combined language instructions, instruction set architecture instructions, machine dependent instructions, micro-instructions, firmware instructions, or Object Code (Object Code) written in any combination of one or more programming languages, including Object oriented programming languages such as: common Lisp, Python, C + +, Objective-C, Smalltalk, Delphi, Java, Swift, C #, Perl, Ruby, and PHP, etc., as well as conventional Procedural (Procedural) programming languages, such as: c or a similar programming language. The computer program instructions may execute entirely on the computer, partly on the computer, as stand-alone software, partly on a client computer and partly on a remote computer or entirely on the remote computer or server.

Referring to fig. 2, fig. 2 is a flowchart of a method for operating a micro-electromechanical microphone headset with a noise reduction function according to the present invention, applied to an environment with a sound source end host 110 and a headset device 120, including the steps of: the audio source host 110 provides two or three wires, wherein at least one of the wires transmits a music signal, and the other wire is a ground wire (step 210); the earphone device 120 is electrically connected to the audio source host 110 through the conducting wire to receive the music signal from the audio source host 110 (step 220); the earphone device 120 continuously receives the ambient noise through the micro-electromechanical microphone with the noise reduction function and generates an ambient sound wave signal corresponding to the ambient noise (step 230); the mems microphone 121 generates an inverse sound wave signal having a phase opposite to that of the ambient sound wave signal, and transmits the inverse sound wave signal and the music signal to the sound generating unit disposed in the ear speaker device 120 (step 240); the earphone device 120 plays the received inverse sound wave signal and the music signal through the sounding unit, so that the played inverse sound wave signal cancels the environmental noise (step 250). Through the above steps, two or three wires are provided to connect the audio source host 110 and the earphone device 120, at least one of the wires is used to transmit music signals, and the other wire is a ground wire, and the earphone device 120 is driven by differential voltage or offset voltage. The mems microphone in the earphone device 120 has an active anti-noise processing capability, and does not need to transmit the received ambient noise to the audio source host 110 through an additional circuit for operation.

The following description is made by way of example with reference to fig. 3 to 6, and fig. 3 is a schematic diagram of a first embodiment of the present invention, as shown in fig. 3. In the first embodiment, the audio source host 110 and the earphone device 120 are electrically connected by three wires (i.e., the first wire 311, the second wire 312, and the third wire 313). The first conductive line 311 is used for transmitting music signals, the second conductive line 312 is used for transmitting VDD, and the third conductive line 313 is a ground line. In addition, when the music signal is a differential signal, two wires are required to transmit the music signal, so the first wire 311 and the second wire 312 can be used for transmission, and the third wire 313 is also a ground wire. For example, the first conductive line 311 may transmit a positive signal, and the second conductive line 312 may transmit a negative signal, in practical implementation, the first conductive line 311 and the second conductive line 312 are parallel lines with equal length, and transmit the same music signal with a phase difference of 180 degrees, so that the transmission rate and the interference resistance can be improved. Next, the noise receiving module 131 receives the ambient noise through the sound receiving element and generates an ambient sound wave signal corresponding to the received ambient noise. Then, the ambient sound wave signal is transmitted to the active anti-noise module 132, the active anti-noise module 132 generates an inverse sound wave signal with a phase opposite to that of the ambient sound wave signal according to the ambient sound wave signal, and the active anti-noise module 132 transmits the music signal received from the first conducting wire 311 and the second conducting wire 312 and the inverse sound wave signal generated by itself to the sound generating module 122, so that the played inverse sound wave signal counteracts the ambient noise, thereby achieving the active anti-noise effect.

Referring to fig. 4, fig. 4 is a schematic view of a second embodiment of the present invention. In the second embodiment, the audio source host 110 and the earphone device 120 are electrically connected by two wires (i.e., a first wire 411 and a second wire 412), wherein the first wire 411 is used for transmitting a music signal with a dc offset, and the second wire 412 is a ground wire. Compared with the first embodiment, the number of wires between the audio source end host 110 and the earphone device 120 is smaller, so that the cost advantage is obtained. Then, as in the first embodiment, the noise receiving module 131 also receives the ambient noise through the sound receiving element and generates an ambient sound wave signal corresponding to the received ambient noise. Then, the ambient sound wave signal is transmitted to the active anti-noise module 132, the active anti-noise module 132 generates an inverse sound wave signal with a phase opposite to the phase of the ambient sound wave signal according to the ambient sound wave signal, and then the music signal received from the first wire 411 and the inverse sound wave signal generated by itself are transmitted to the sound generating module 122 together, so that the played inverse sound wave signal counteracts the ambient noise, thereby achieving the active anti-noise effect.

As shown in fig. 5, fig. 5 is a schematic view of a third embodiment of the present invention. In this third embodiment, it differs from the first embodiment of fig. 3 only in the number of micro-electromechanical microphones. In the third embodiment, the earphone device 120 includes a first mems microphone 121a and a second mems microphone 121b, which are electrically connected to each other. The second mems microphone 121b can receive the residual noise and generate a corresponding error signal according to the residual noise to be transmitted back to the first mems microphone 121a, so that the active anti-noise module of the first mems microphone 121a can compensate the anti-noise effect affected by the delay. For example, when the residual noise is received, an error signal is generated to make the first micro-electromechanical microphone 121a control the output time of the inverted sound wave signal to shorten the delay, or adjust the inverted sound wave signal according to the error signal, and so on. In addition, since the number of the micro-electromechanical microphones is different, the electrical connection methods of the wires are slightly different, and in the third embodiment, as shown in fig. 5, the first wire 511 and the second wire 512 are both electrically connected to the first micro-electromechanical microphone 121a and the second micro-electromechanical microphone 121b at the same time, and the third wire 513 serving as a ground wire is electrically connected to the sound generating module 123, the first micro-electromechanical microphone 121a, and the second micro-electromechanical microphone 121b at the same time.

In addition, as shown in fig. 6, fig. 6 is a schematic view of a fourth embodiment of the present invention. In this fourth embodiment, the difference from the third embodiment is only in the number of wires. In the fourth embodiment, there are only two wires between the audio source host 110 and the earphone device 120, which are the first wire 611 and the second wire 612. The first wire 611 is electrically connected to the first mems microphone 121a and the second mems microphone 121b, and the second wire 612, which is a ground wire, is electrically connected to the first mems microphone 121a, the second mems microphone 121b and the sound module 123. In this case, it is clear that only two wires (i.e., the first wire 611 and the second wire 612) are required between the audio source side host 110 and the earphone device 120 even in the case of multiple micro-electromechanical microphones. That is, the active anti-noise processing is directly performed by the micro-electromechanical microphone inside the earphone device 120, and the audio signal does not need to be transmitted between the audio source terminal host 110 and the earphone device 120 through an additional wire, so that the line loss, the cost and the signal delay can be effectively reduced.

In summary, it can be seen that the difference between the present invention and the prior art is that at least one of the wires is used for transmitting music signals, and the other wire is a ground wire, and the earphone device is driven by differential voltage or offset voltage. The micro-electromechanical microphone in the earphone device has active anti-noise processing capability, received environmental noise is not required to be transmitted to the sound source end host through an additional line for operation, the problems in the prior art can be solved through the technical means, and the technical effects of reducing line loss, cost and signal delay are achieved.

Although the present invention has been described with reference to the above embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention.

Claims

1. A mems microphone headset system with noise reduction, the system comprising:

the audio source end host is used for providing two or three wires, wherein at least one wire of the wires transmits a music signal, and the other wire of the wires is a grounding wire; and

an earphone device electrically connected to the audio source terminal host through the wire, the earphone device comprising:

a microelectromechanical microphone, comprising:

the noise receiving module is electrically connected with the lead and continuously receives the ambient noise through at least one sound receiving element so as to generate an ambient sound wave signal corresponding to the ambient noise; and

an active anti-noise module electrically connected to the noise receiving module and the wire for receiving the music signal from the wire transmitting the music signal, generating an opposite phase sound wave signal opposite to the phase of the environmental sound wave signal, and transmitting the opposite phase sound wave signal and the music signal; and

and the sound-emitting module is electrically connected with the active anti-noise module and used for receiving the reversed-phase sound wave signal and the music signal, and simultaneously playing the received reversed-phase sound wave signal and the music signal through a sound-emitting monomer so that the played reversed-phase sound wave signal counteracts the environmental noise.

2. The mems microphone headset system of claim 1, wherein the conductive wires comprise a first conductive wire, a second conductive wire and a third conductive wire, the first conductive wire is used for transmitting the music signal, the second conductive wire is used for transmitting a power voltage, and the third conductive wire is the ground wire.

3. The mems microphone headset system according to claim 1, wherein the conductive lines include a first conductive line, a second conductive line and a third conductive line, the first conductive line and the second conductive line are used for transmitting the music signal as a differential signal and driving the headset device with a differential voltage, and the third conductive line is the ground line.

4. The mems microphone headset system according to claim 1, wherein the conductive lines include a first conductive line and a second conductive line, the first conductive line is used for transmitting the music signal with a dc offset and driving the headset device with an offset voltage, and the second conductive line is the ground line.

5. The noise reduction mems microphone earphone system of claim 1, wherein the sound receiving component is electrically connected to an analog front end circuit, an analog-to-digital converter, the active anti-noise module and an amplifier in sequence, the active anti-noise module comprising inversion, delay, gain, time control, equalization, signal superposition, format conversion and filtering operations for noise processing and audio processing.

6. The mems microphone headset system of claim 1, wherein the headset device further comprises another mems microphone electrically connected to the mems microphone and the conductive wire, and continuously receiving a residual noise to generate a corresponding error signal, and transmitting the error signal to the mems microphone for the active anti-noise module to perform the delay compensation process.

7. An operating method of a micro-electro-mechanical microphone earphone with a noise reduction function is applied to an environment with an audio source end host and an earphone device, and is characterized in that the operating method of the micro-electro-mechanical microphone earphone with the noise reduction function comprises the following steps:

the sound source end host machine is provided with two or three wires, wherein at least one wire of the wires transmits a music signal, and the other wire of the wires is a grounding wire;

the earphone device is electrically connected with the sound source end host through the conducting wire so as to receive the music signal from the sound source end host;

the earphone device continuously receives an environment noise through at least one micro-electro-mechanical microphone with a noise reduction function and generates an environment sound wave signal corresponding to the environment noise;

the micro-electro-mechanical microphone generates an inverse sound wave signal with the phase opposite to that of the environment sound wave signal, and transmits the inverse sound wave signal and the music signal to a sounding monomer arranged in the earphone device; and

the earphone device simultaneously plays the received reverse sound wave signal and the music signal through the sounding monomer, so that the played reverse sound wave signal counteracts the environmental noise.

8. The method as claimed in claim 7, wherein the conductive wires include a first conductive wire, a second conductive wire and a third conductive wire, the first conductive wire is used for transmitting the music signal, the second conductive wire is used for transmitting a power voltage, and the third conductive wire is the ground wire.

9. The method as claimed in claim 7, wherein the conductive wires include a first conductive wire, a second conductive wire and a third conductive wire, the first conductive wire and the second conductive wire are used to transmit the music signal as a differential signal, and the earphone device is driven by a differential voltage, and the third conductive wire is the ground wire.

10. The method as claimed in claim 7, wherein the conductive wires include a first conductive wire and a second conductive wire, the first conductive wire is used to transmit the music signal with a dc offset and drive the earphone device with an offset voltage, and the second conductive wire is the ground wire.

11. The method as claimed in claim 7, wherein the mems microphone is electrically connected to an analog front end circuit, an analog-to-digital converter, an active noise cancellation module and an amplifier in sequence for amplifying and outputting the inverted acoustic wave signal, and the active noise cancellation module comprises inversion, delay, gain, time control, equalization, signal superposition, format conversion and filtering operations for noise processing and audio processing.

12. The method as claimed in claim 7, wherein the earphone device further comprises another mems microphone electrically connected to the mems microphone and the conductive wire, and continuously receiving a residual noise to generate a corresponding error signal, and transmitting the error signal to the mems microphone for the mems microphone to perform the delay compensation process.